(i) Technical Field
The present invention relates to a color processing apparatus, a color processing method, and a non-transitory computer readable medium.
(ii) Related Art
Input/output characteristics of an output device are approximated as a color conversion model using a pair of color values, namely, a color value given to the output device and a measured color value that is a value obtained by measuring a color output from the output device. Typical color conversion models may be broadly classified into physical models and statistical models. A typical example of the physical models is a Neugebauer halftone dot model. For example, the color values of 16 colors obtained from the combinations of 100% and 0% colorants used in the output device are given to the output device to obtain measured color values. A color conversion model is created from the pairs of 16 color values and measured color values. One example of the statistical models is a neural network. A color value to be given to the output device is given to the neural network, and the corresponding measured color value is given as a supervisory signal for learning, resulting in the input/output characteristics of the output device being approximated. The statistical models require a larger number of pairs of color values given to the output device and measured color values than the physical models, and require a large amount of processing for constructing a color conversion model but achieve high accuracy.
Accordingly, the number of measured color values and accuracy are contradictory to each other. For example, a Neugebauer model in which the color space is divided into subspaces and a Neugebauer model is constructed for each of the subspaces, called a cellular Neugebauer model, has also been developed. This model provides higher accuracy but requires a larger number of measured color values than the model that employs the entire color space.